<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script>
        //除了这5个为false 其他全为true
        console.log(Boolean(''));//false
        console.log(Boolean(0));//false
        console.log(Boolean(NaN));//false
        console.log(Boolean(null));//false
        console.log(Boolean(undefined));//false
        console.log()


    </script>
</head>
<body>

</body>
</html>